Clinical Study to Evaluate the Effect of pH on Pain Upon Local Anesthetic Administration.
Status:
Terminated
Trial end date:
2014-11-01
Target enrollment:
Participant gender:
Summary
When one receives a local anesthetic, such as novocaine for a dental procedure, there is a
burning painful sensation experienced upon injection of the local anesthetic. We are trying
to understand the role of pH (how acidic a solution is) in the production of pain during
local anesthetic administration. We hypothesize that less acidic solutions produce less
burning. We also want to determine whether or not the pH of the solution affects the rate of
onset of the local anesthesia. We will recruit subjects from patients who have a clinical
indication for lumbar medial branch (LMB) nerve blocks, procedures frequently performed at
the Massachusetts General Hospital Center for Pain Medicine. For each patient, three nerve
blocks are administered at adjacent spinal levels, typically using either lidocaine or
bicarbonate-buffered lidocaine as the local anesthetic. We will add a saline control as part
of the research procedure and then provide lidocaine at the control location before
continuing with the nerve blocks. This clinical procedure offers an ideal opportunity to
compare the effects of the three solutions. There will be almost no deviation from the
standard clinical procedure. After the injection of each solution, the pain score on
administration of the medication will be recorded immediately. We will also provide a
continuous stimulation (pin taps) after the local anesthetic injection and record when the
patient experiences hypoesthesia (reduced sensation) and anesthesia (absent sensation).
Finally, we will record the pain score upon reinsertion of a needle to mark the precise
location (part of the clinical procedure) one minute after the local anesthetic injection.
All data will be collected during the a single clinical visit.
The study will conclude when 60 subjects have successfully been tested. Data will be reviewed
annually.